How to write an Internal Frame Listener in Java?

**Soumen** · 12-02-2010

Hello friends,
I am new to your forum. I have done some basic things in Java. But I am not able to write an internal frame..!!! I want a listener which would listen for an events that occur when the anything happens with the Window. Like if the windows has been shown for the first time, activated, or deactivated. Hope that you guys got the point that I am saying.! Please tell me how to write an Internal Frame Listener in Java.?? Help me soon as possible.

**CodGuru** · 13-02-2010

Hi 'Soumen', Welcome to this forum...
If you know about the WindowListener which is almost similar to an InternalFrameListener, then it would take no time for you to understand. As you know, when anything happens to the window that event is listened by the internal frame listener just like the window listener. The events of windows can be if it is shown for the first time, disposed of, iconified, deiconified, activated, or deactivated. You can say that internal frame listeners are very similar to WindowListeners and several Swing programs have window listeners.

**void** · 13-02-2010

I have provided you with the sample of the coding that requires InternalFrameEvent. Hope that you will get some help from this coding :

Code:

public InternalFrameEventTrial(String title) {
        super(title);

        desktop = new JDesktopPane();
        desktop.putClientProperty("JDesktopPane.dragMode",
                                  "outline");

        desktop.setPreferredSize(new Dimension(desktopWidth, desktopHeight));
        setContentPane(desktop);

        createDisplayWindow();
        desktop.add(displayWindow); 
        Dimension displaySize = displayWindow.getSize();
        displayWindow.setSize(desktopWidth, displaySize.height);
    }

**Warner** · 13-02-2010

I am providing you the methods that are used for the InternalFrameListener Interface. Also an InternalFrameAdapter is the corresponding adapter class of this listener. The following are the methods of an InternalFrameListener Interface :

internalFrameOpened(InternalFrameEvent) - This method is called just after the listened-to internal frame has been shown for the first time.
internalFrameClosed(InternalFrameEvent) - When the listened-to internal frame has been disposed of, then this method is called.
internalFrameClosing(InternalFrameEvent) - This method is called in response to a user request that the listened-to internal frame be closed.
internalFrameIconified(InternalFrameEvent) - This method is called just after the listened-to internal frame is iconified.
internalFrameDeiconified(InternalFrameEvent) - When listened-to internal frame is deiconified then this method is called.

**Allan.d** · 13-02-2010

I think that you will understand more after looking at the following code. The following code explains the internal frame event handling. So have a look on the code below :

Code:

public class InternalFrameEventTrial ...
		     implements InternalFrameListener ... {
    ...

    public void internalFrameClosing(InternalFrameEvent ie) {
	displayMessage("Internal frame closing", ie);
    }

    public void internalFrameClosed(InternalFrameEvent ie) {
	displayMessage("Internal frame closed", ie);
	listenedToWindow = null;
    }

    public void internalFrameOpened(InternalFrameEvent ie) {
	displayMessage("Internal frame opened", ie);
    }

    public void internalFrameIconified(InternalFrameEvent ie) {
	displayMessage("Internal frame iconified", ie);
    }

    public void internalFrameDeiconified(InternalFrameEvent ie) {
	displayMessage("Internal frame deiconified", ie);
    }

    public void internalFrameActivated(InternalFrameEvent ie) {
	displayMessage("Internal frame activated", ie);
    }

    public void internalFrameDeactivated(InternalFrameEvent ie) {
	displayMessage("Internal frame deactivated", ie);
    }

    void displayMessage(String prefix, InternalFrameEvent ie) {
	String str = prefix + ": " + ie.getSource(); 
	display.append(str + newline);
    }

    public void actionPerformed(ActionEvent ie) {
	if (SHOW.equals(ie.getActionCommand())) {
	    ...
	    if (listenedToWindow == null) {
	        listenedToWindow = new JInternalFrame("Event Generator",
	        				      true,  
	        				      true,  
	        				      true,  
	        				      true);
        	listenedToWindow.setDefaultCloseOperation(
        				WindowConstants.HIDE_ON_CLOSE);

	        listenedToWindow.addInternalFrameListener(this);
	        ...
	    }
	} 
	...
    }
}

**absolute55** · 13-02-2010

I want to tell you more about the Internal Frame Listener which is used in Java. An AWTEvent that adds support for JInternalFrame objects as the event source. As said earlier the InternalFrame object is much similar to the WindowEvent, hence the JInternalFrame class has the same event types as WindowEvent but the only thing that they have different IDs for their use. One thing you would have to keep in mind that Swing which are going to release in future may have compatible issues with the Serialized objects of this class. Hope that this information was helpful for you.!!